1. Field of the Invention
The present invention relates generally to an apparatus and a method for supporting Automatic Repeat reQuest (ARQ) in a wireless communication system. More particularly, the present invention relates to an apparatus and a method for supporting ARQ for an ARQ block or an ARQ sub-block in the wireless communication system.
2. Description of the Related Art
A wireless communication system is subject to data error according to a channel condition of a radio resource carrying the data. To raise transmission reliability, the wireless communication system controls and recovers from the data error using an Automatic Repeat reQuest (ARQ) scheme.
Using the ARQ scheme, a receiving stage informs a transmitter stage of reception success or failure of an ARQ block received from the transmitting stage. For example, when the ARQ block received from the transmitting stage has no error, the receiving stage sends ACKnowledge (ACK) information to the transmitting stage. Conversely, when the ARQ block received from the transmitting stage is erroneous, the receiving stage sends Negative ACK (NACK) information to the transmitting stage. Herein, a series of the operations of the receiving stage which informs the transmitting stage of the success or failure of the packet reception is referred to as ARQ feedback.
Upon confirming the packet successfully received at the receiving stage based on the ARQ feedback, the transmitting stage sends a new packet.
When confirming the packet failed to arrive at the receiving stage based on the ARQ feedback, the transmitting stage retransmits the failed packet to the receiving stage. In so doing, the transmitting stage can recognize that the receiving stage fails to receive the packet due to the poor channel condition of the receiving stage. In this regard, the transmitting stage requires a technique for retransmitting the packet by taking account of the channel condition.